A small timecode template class

src/common/timecode.h

@@ -0,0 +1,170 @@
+/*
+   mkvmerge -- utility for splicing together matroska files
+   from component media subtypes
+
+   Distributed under the GPL
+   see the file COPYING for details
+   or visit http://www.gnu.org/copyleft/gpl.html
+
+   class definition for the basic_timecode_c template class
+
+   Written by Moritz Bunkus <moritz@bunkus.org>.
+*/
+
+#ifndef MTX_COMMON_TIMECODE_H
+#define MTX_COMMON_TIMECODE_H
+
+#include "common/common_pch.h"
+
+#include <boost/operators.hpp>
+
+template<typename T>
+class basic_timecode_c
+  : boost::totally_ordered< basic_timecode_c<T>
+  , boost::arithmetic< basic_timecode_c<T>
+  > >
+{
+private:
+  T m_timecode;
+  bool m_valid;
+
+  explicit basic_timecode_c<T>(T timecode)
+    : m_timecode{timecode}
+    , m_valid{true}
+  {
+  }
+
+  basic_timecode_c<T>(T timecode, bool valid)
+    : m_timecode{timecode}
+    , m_valid{valid}
+  {
+  }
+
+public:
+  basic_timecode_c<T>()
+    : m_timecode{}
+    , m_valid{}
+  {
+  }
+
+  // validity
+  bool valid() const {
+    return m_valid;
+  }
+
+  void reset() {
+    m_valid    = false;
+    m_timecode = 0;
+  }
+
+  // deconstruction
+  T to_ns() const {
+    return m_timecode;
+  }
+
+  T to_ns(T value_if_invalid) const {
+    return m_valid ? m_timecode : value_if_invalid;
+  }
+
+  T to_us() const {
+    return m_timecode / 1000;
+  }
+
+  T to_ms() const {
+    return m_timecode / 1000000;
+  }
+
+  T to_s() const {
+    return m_timecode / 1000000000;
+  }
+
+  T to_mpeg() const {
+    return m_timecode * 9 / 100000;
+  }
+
+  // arithmetic
+  basic_timecode_c<T> operator +=(basic_timecode_c<T> const &other) {
+    if (!m_valid || !other.m_valid)
+      reset();
+    else
+      m_timecode += other.m_timecode;
+    return *this;
+  }
+
+  basic_timecode_c<T> operator -=(basic_timecode_c<T> const &other) {
+    if (!m_valid || !other.m_valid)
+      reset();
+    else
+      m_timecode -= other.m_timecode;
+    return *this;
+  }
+
+  basic_timecode_c<T> operator *=(basic_timecode_c<T> const &other) {
+    if (!m_valid || !other.m_valid)
+      reset();
+    else
+      m_timecode *= other.m_timecode;
+    return *this;
+  }
+
+  basic_timecode_c<T> operator /=(basic_timecode_c<T> const &other) {
+    if (!m_valid || !other.m_valid)
+      reset();
+    else
+      m_timecode /= other.m_timecode;
+    return *this;
+  }
+
+  basic_timecode_c<T> abs() const {
+    return basic_timecode_c<T>{std::abs(m_timecode), m_valid};
+  }
+
+  // comparison
+  bool operator <(basic_timecode_c<T> const &other) const {
+    return !m_valid &&  other.m_valid ? true
+         :  m_valid && !other.m_valid ? false
+         :  m_valid &&  other.m_valid ? m_timecode < other.m_timecode
+         :                              false;
+  }
+
+  bool operator ==(basic_timecode_c<T> const &other) const {
+    return (!m_valid && !other.m_valid) || (m_valid && other.m_valid && (m_timecode == other.m_timecode));
+  }
+
+  // construction
+  static basic_timecode_c<T> ns(T value) {
+    return basic_timecode_c<T>{value};
+  }
+
+  static basic_timecode_c<T> us(T value) {
+    return basic_timecode_c<T>{value * 1000};
+  }
+
+  static basic_timecode_c<T> ms(T value) {
+    return basic_timecode_c<T>{value * 1000000};
+  }
+
+  static basic_timecode_c<T> s(T value) {
+    return basic_timecode_c<T>{value * 1000000000};
+  }
+
+  static basic_timecode_c<T> min(T value) {
+    return basic_timecode_c<T>{value * 60 * 1000000000};
+  }
+
+  static basic_timecode_c<T> h(T value) {
+    return basic_timecode_c<T>{value * 3600 * 1000000000};
+  }
+
+  static basic_timecode_c<T> mpeg(T value) {
+    return basic_timecode_c<T>{value * 100000 / 9};
+  }
+
+  static basic_timecode_c<T> factor(T value) {
+    return basic_timecode_c<T>{value};
+  }
+};
+
+typedef basic_timecode_c<int64_t> timecode_c;
+
+#endif  // MTX_COMMON_TIMECODE_H